If a language is missing Bloom filters or epoll_wait(2), anyone can offer that in a fairly self-contained library. But if a language is missing something like l

If a language is missing Bloom filters or epoll_wait(2), anyone can offer that in a fairly self-contained library. But if a language is missing something like lambdas, pattern matching, exception handling, move semantics, or coroutines, that’s a lot harder to add in a usable and efficient way without actually extending the grammar and the code generator. Those are the things that make a language harder to learn at first but then replace a lot of boilerplate that should (usually) be beneath our notice.